I'm certainly no expert but I have installed two sets of Hooker harnesses in two airplanes and flown quite a bit of hard aerobatics in both.
A ratcheting belt is one of the best investments you'll ever make if you plan to do any negative g maneuvering. If all you plan to do is float over the top then don't worry about it. But, if you want to hold those 45 degree downlines, fly a decent slow roll, or do any outside figures, you MUST have a ratcheting belt. You simply CANNOT pull hard enough on a standard lap belt to secure your butt in the seat for aggressive negative g maneuvering.
You DO NOT want a ratcheting belt that comes straight off the fuselage bottom and runs across your thighs. You'll probably give yourself a blood clot or worse if you try that approach!
The ratcheting belt needs to cinch down across your hips. Otherwise, when you push any significant negative g, your butt will try and float up and out along the plane of the seat back. Not good. The belt needs to hold you both down and back into both the back and the bottom of the seat.
I use the same attach point for both belts. The risk I accept is a potential failure of the attach point. Any other failure, of the seatbelt or the latching system, does not depend on having independent attach points for the two belts. I think that's an entirely acceptable risk.
My advice - buy a Crow or a Hooker and double up on the same, plans built attach point. You'll be happy with that and completely safe within the limits of RV approved aerobatics.
Tampa (Wimauma), Florida
RV-4 N212CS (sold)
RV-8 N184RK (flying)
Flying an A320 to pay the bills
Exempt and gladly donating anyway - Current through March 2020